Clutch facing and process of making the same



Oct. 27, 1936. J. A. LUNN 2,058,701

CLUTCH EAGING AND PRocEss oF MAKING THE SAME Filed June 25, 1954 Patented Oct. 27, 1936 CLUTCH FACI'NG AND PROCESS OF ll/IAKING THE SAME John A. Lunn, Cambridge, Mass., assigner, by mesne assignments, to Raybestos-Manhattan, Inc., Passaic, N. J., a corporation of New Jersey Application June 23, 1934, Serial No. 732,074

Claims. (Cl. 192-107) This invention relates to the manufacture of improved clutch facings or clutch rings, and especially those of the woven disk type and of the character used in disk clutches and brakes.

, For convenience, such rings will hereafter be referred to as clutch facings.

A number of different clutch facings have, from time to time, been suggested and in general they may be classied in two groups. One class eme a contacting surface free from metallic parts which tend to cut .or score the adjoining driving plates. Yet an additional object is to provide a clutch facing that may be ground to cut or score the adjoining driving plates. Yet an additional object is to provide a clutch facing that may be ground to a true fiat surface without weakening the staples forming the joint; Other objects and advantageswill appear as the description probraces annular rings stamped from sheets o-r ceeds. l0 boards of asbestos made on a paper machine and I have discovered an improved method of joinsubsequently treated to impart thereto the deing the two ends of the Woven strip or fabric sired coefficient of friction and Wearing resistby which Ya highly efiicient facing is produced. ance. The other class is made from a strip of This result isl accomplished by compressing the j5- fabric, woven to the required Width, and then staples and the adjacent body of the annulus 15 shaped and molded into the form of a flat ring. whereby the fabric mass is, in the compressed The yarn employed is long bered asbestos rearea, rendered dense and retentive of the fasteninforced if necessary with cotton or other` fibers, ing staples, and its surface is positioned below and usually associated with one or more metallic that of the work surface of the clutch facing.

wires running parallel therein. Preferably the indentations thus produced are 20 I have found that a woven strip, molded to filled With a plastic mass which, when indurated, form, is superior to the stamped or died ring for forms a resistent Compound With the Dieper C0- the reason that it provides two selvage edges efficient of friction and hardness. In this manner around the entire ring. The joining of the ends the metalli@ Staples are pOSii/ieneel in the bOCly of this strip, however, to complete the ring preof the facing and do not contact with the metal 25 i sents special difficulties since the ring is subjected plates Of the dl'iVing 01 driven paris Of the while it is in use to severe strains tending to mechanism. open the joint and thus destroy the usefulness T0 illustrate my illVellliiOn, I lefei t0 the of the facing. 'Ihe usual practice has been to eeeonlpenyillg draWingl unite the ends of the strip by fasteners so in- Figure 1 represents a WOVen and J'Oined felling 30 serted that they either wear rapidly while in use after impregnation but before molding. and thus break after a short time, or they are Fig. 2 iS a SeeliiOnel VieW 0n the line 2-2 0f so arranged as to bend when an unusual strain Fig. 1 before pressure has been applied in the is placed upon them sufcient to allow the joint mould.

to open. An even more important objection to Fig. 3 is a sectional view on the same line after 35 a facing thus fastened arises from the fact that the molding operation is Complete. the exposed surface of the staples forming the Fig. 4 iS e Sectional VieW in the line 4 4 0f metallic fastening tend to out a, groove or in- Fig. 5 after the recess formed by the bosses of dentation in the surface of the driving or driven the mould have been lled.

metallic face with which it is made to Contact, Fie. 5 is a View of the finished facing showing and produces thereon what is technically known lille Side that Centeeifs ille driving Dieteas scoring or grooving. The Woven fabric is cut and shaped to form The danger of thus damaging the metallic face an annular ring lll, the ends ll being fitted in of the contacted plates is greatest in the soabutting relation to each other with an accuracy called initial or run-in period. During this pethat DIOViCleS e Continuous uniform Surface 45 riod high pressure areas are developed more parthroughout the circumference of the ring. The ticularly at the joint in the facing and the extwo abutting ends Il are then joined by metalposed portions of the metallic facing or staples lic staples l2 spaced at predetermined intervals wear grooves in the plates. as may be seen in Fig. 1, and inserted by methods It is the object of this invention to provide ordinarily employedinthis art. Inthis condition 50 a clutch facing of the woven-fiber type which the facing is now thoroughly impregnated with will be securely joined by metallic fasteners which a bonding material capable of being solidified are fully protected from wear and abrasion by by heat or other well known means and is superthe moving parts of the driving mechanism. A cially dried. The composition of such bonding further object is to provide a clutch facing with materials is not a part of this invention, is Well 55 understood in the art, and will not be here further described.

An alternative method of preparing the Woven and joined ring is to impregnate the yarn during the process of weaving, the joined product being then dried to a proper consistency for subsequent handling. Such a facing is shown in Fig. 1. A sectional view showing the position of the staples I2 relative to the body I of the ring is shown in Fig. 2.

The mould in which the facing thus produced may be finally shaped, is provided at one point in its circumference with a number of bosses or bars corresponding to the number of metallic staples which appear in the facing, and so positioned that each bar contacts with an individual Staple at the joint. When pressure is applied, the ring is given a permanent and desired shape and the bosses of the mould drive the individual staples I2 below the surface of the facing to a sufficient depth to avoid being weakened when the surfaces are ground and finished, and to avoid their contacting with the plate of the driven or driving member of the mechanism when assembled.

The indentations indicated at I3 in the surface of the facing occasioned by the depression of the staples I2 are shown in Fig. 3 and are filled with any of the Well known oxidizing oil plastic mixtures, or rubber compositions indicated at I4, as seen in Fig. 4. The facing is then baked in accordance with any of the usual methods now employed for this purpose, the finished facing appearing as shown in Fig. 5.

The hardened article is now ground to parallel surfaces and furnishes a, friction element of wide utility, free from the danger of scoring incident to the Contact of metallic fasteners with the friction producing surface.

I claim:

1. A clutch facing of the woven-fabric-joined type having indentations below the surface level, staple fasteners in said indentations, said indentations being filled with a friction producing material.

2. In a process for making an annular friction producing surface, the steps which comprise joining a strip of woven impregnated fabric into an annulus by means of metallic staples, compressing said staples together with the adjacent annulus by pressure in a mould, filling the recesses thus produced in the surface of the annulus with a plastic mass, and baking said annulus.

3. An annular friction element comprising an interrupted ring of fabric having cooperating indentations in the Workng face thereof adjacent the ends of the ring and staples joining the ends together located in the indentations, the upper surface of the staples being beneath the working surface of the ring'.

4. An annular friction element comprising an interrupted ring of fabric having cooperating indentations in the Working face thereof adjacent the ends of the ring and staples joining the ends together located in the indentations, said indentations being lled with a baked plastic mass.

5. An annular clutch facing comprising an interrupted ring of indurated friction fabric, a cooperating indentation the axis of which forms a cord of the ring, adjacent the ends thereof, and a staple joining the ring located in the indentation, said indentation being deeper than the thickness of the staple.

JOHN A. LUNN. 

